Method, Fuel, and Apparatus for Grilling With Chipped Charcoal

ABSTRACT

Described herein is a method for isolating high carbon chipped wood charcoal fuel suitable for grilling food. According to one aspect, the method involves removing pyrolyzed wood charcoal from a kiln wherein the pyrolyzed wood charcoal comprises lumps, chips, smaller pieces, and dust particles. The pyrolyzed wood charcoal is passed over a first sieve that is configured to separate the lumps from the chips, smaller pieces and dust particles. The chips, smaller pieces and dust particles are then passed over a second sieve that is configured to separate the chips from the smaller pieces and dust particles. The resulting chipped wood charcoal is consistently sized to be small enough to pass through a food supporting grill grate and supportable by an underlying grid support, thereby allowing refueling while grilling without interruption.

BACKGROUND

Grilling enthusiasts have long considered solid wood charcoal as anideal fuel for optimum flavor, moisture retention, and texture whengrilling meats and vegetables. Unlike natural gas or propane, whichgenerates a lot of moisture as a result of the combustion thereof, solidwood charcoal generates a very hot, dry heat that is ideal for searingmeat and vegetables and consequent moisture retention while cooking.Charcoal briquettes, which are often made by compressing coal dust,sawdust, charcoal dust with binding agents, are preferred by many forgenerating a steady heat over a long period of time, but can impartunpleasant chemical flavors and odors to food. Solid natural woodcharcoal, though, generates higher heat than briquettes, for searing andfaster cooking, and imparts neutral or wood smoke flavor to foods thatmany people prefer.

Solid wood charcoal is created by a process known as pyrolysis: theheating wood pieces to a high temperature in a low oxygen environment.This ancient process removes water and many volatile compounds andchanges the chemical structure of the wood. Natural wood charcoal can beone-fourth the weight of the wood it is made from, and is naturally verybrittle. Because it is so brittle, when natural wood charcoal is handledwhen removing from the kiln, and during processing or packaging, smallpieces of wood charcoal chip away from exterior surfaces of the largerpieces. Because the outer-most portions near the surface of the woodcharcoal are more directly exposed to the minimal flow of air throughthe kiln, they provide easier egress for volatiles from the wood thaninterior portions. These outer-most portions are therefore higher inconcentration in fixed-carbon as a percentage of mass than the woodcharcoal pieces as a whole, and are consequently also more fragile andmore likely to chip away from the solid charcoal lumps. These smallpieces would fall through traditional charcoal support structures; theyare generally considered by those in the field to be unusable in thisform as a grilling fuel source because they would fall through the fuelsupport structure in the grilling apparatus. Because it was consideredto be unusable, this “chipped wood charcoal” is regarded by companiesinvolved in producing natural wood charcoal as an undesirable byproductof production and is therefore sold, along with smaller particles anddust, at very low cost to manufacturers of charcoal briquettes oractivated carbon filters.

SUMMARY

Described herein are methods and apparatuses for grilling food usingchipped wood charcoal, a novel and superior fuel for grilling. Thechipped wood charcoal fuel is gathered from chipped pieces of woodcharcoal formed by pyrolysis of natural wood. The chipped wood charcoalpieces have a high concentration of fixed carbon and may range in sizefrom about one-fourth to about three-eighths of an inch in its longestdimension. Production of such fuel involves a novel multi-step processfor separating the desirable small pieces of high carbon chipped woodcharcoal from larger lumps of wood charcoal and still smaller pieces anddust that would fall through the support structure described herein. Thesupport structure for the chipped wood charcoal that is described hereinmay be disposed for use with existing grilling apparatuses. Finally, amethod of cooking food is described herein, which includes a novelmethod of adding chipped charcoal to the fuel support structure, througha grill grate used for supporting food, before and during cooking.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cross-section of segment of a food grillingapparatus including a chipped charcoal support.

FIG. 2 shows a flow chart diagram of an exemplary method for isolatinghigh-carbon chipped wood charcoal.

FIG. 3 shows a flow chart diagram of an exemplary method for grillingfood.

DETAILED DESCRIPTION

Modern chefs and home cooks often prefer to grill meat and vegetablesover natural solid wood charcoal. The inventor of the apparatus andtechniques described herein successfully developed and commercialized anapparatus, previously disclosed in U.S. Pat. No. 6,161,534, which isfully incorporated herein by reference, designed for converting anatural gas or propane grill to cook with natural solid wood charcoal.The inventor, who has also successfully developed multiple brands ofnatural solid wood charcoal for grilling, recognized that chipped woodcharcoal, previously understood to be an “unusable” byproduct of woodcharcoal production, is not only usable, but is in many ways a superiorfuel source for food grilling. These superior properties include, amongother things, faster lighting, hotter burning, and, due to an extremelyhigh concentration of fixed carbon, more pure combustion. However,several problems existed that heretofore had not been recognized oraddressed. First, pieces of wood charcoal of appropriate size must bedetermined and isolated such that fuel may be added through a foodgrate, while still being supportable below the food grate. Second, agrid must be designed for supporting the small pieces of chipped woodcharcoal while enabling sufficient airflow for optimum combustion.Finally, a method for cooking over chipped wood charcoal, uniquelyenabling prolonged cooking by refueling without lifting the food grillgrate or interrupting the cooking process, by passing the fuel directlythrough ordinary, traditional, food supporting grill grates.

FIG. 1 shows a segment of food grilling apparatus 10 in cross-section.It should be noted that this diagram is not to scale. Apparatus 10includes an ordinary food support grill grate 12 having consistentlyspaced bars for supporting food such as meats and/or vegetables. A grid14 includes bottom perforated portion 16 with perforations 18 and anupstanding side edge 17. Chipped wood charcoal 20 is shown supported bybottom perforated portion 16. Supports 19, which may be an existingbriquette support grate or heat spreaders of a gas grill, support grid14. As described, therefore, grid 14 may be added to any traditionalstandard solid fuel or gas burning grilling apparatus, for supportingchipped wood charcoal as an alternative fuel source.

Grid 14, as viewed from above, may be square, rectangular, or othershape, formed from perforated metal. In one embodiment, grid 14 isformed from 14 to 20-gauge steel or aluminum with three-eights inchround or five-sixteenths inch square perforations that make up 39% to44% of the surface area of the perforated portions of the sheet. It hasbeen discovered by the present inventor that these characteristics allowa balance of airflow for maximum heat generation with minimalfall-through of the chipped wood charcoal fuel, while also maintainingstructural integrity of grid 14 under the very high temperature extremesgenerated while grilling. Edges 17 may rise from all sides of grid 14 adistance of one-half inch. Edges 17 may vary in construction. Inexemplary embodiments, edges 17 may be formed from the same sheet ofmetal as bottom perforated portion 16, and simply bent up and welded atthe corners. In this case, edges 17 may be perforated or not perforated.In other embodiments, edges 17 may be a spot-welded half-inch metalround or square bar, or bent-metal sheet, which may vary with consumerverses commercial chef requirements. Edges 17 provide structuralintegrity to grid 14 as it experiences extreme heat changes andgradients. Although shown extending up from bottom perforated portion16, grid 14 may be oriented extending down if it is desired to lift fuelsupporting bottom perforated portion up from supports 19.

Chipped wood charcoal fuel 20, in various embodiments, is created from100% natural virgin hardwoods which have been aged for 12-18 monthsprior to pyrolysis processing in kilns. Because kiln firing techniquesand because only hardwoods are used, the chipped wood charcoal fuel hasa higher (ultra) fixed carbon component and fewer volatiles than typicalwood charcoal found in stores and restaurant supply houses.Substantially all, but at least a majority of the pieces of chipped woodcharcoal fuel 20 is sized between one quarter to three-eighths of aninch. This enables it to easily drop through grill grate 12 and onto thegrid 14, eliminating any need to stop and lift grill grate 12 to refuel.

FIG. 2 shows a flowchart 30 illustrating by way of example a method forproducing the novel chipped wood charcoal fuel envisioned. The methodstarts at start block 32 and flows to operation 34 wherein natural woodis pyrolyzed in kilns to form natural wood charcoal lumps. These lumpsare brittle and light-weight with outer-most portions being very brittleand very high in fixed carbon. As a result while removing wood charcoallumps from the kiln in operation 36, smaller pieces, referred herein as“chipped wood charcoal,” of these outer most portions of the charcoallumps fall away. In operation 38, the chipped wood charcoal and smallerpieces and dust are separated from lump wood charcoal. In oneembodiment, to separate the chips from lumps, the lumps and chips arepassed over a first screen or sieve to selectively allow chipped woodcharcoal, smaller pieces, and dust to fall through the sieve whileretaining the larger charcoal lumps. In one embodiment, the first sieveis configured to remove pieces that are about three-eighths of an inchin their longest dimension or smaller. The larger lumps may then bepackaged as standard solid lump wood charcoal as shown in operation 42.

In operation 40, the combined chipped wood charcoal and smaller piecesand dust are passed over a second screen or sieve. In one embodiment,the second sieve is configured to remove pieces smaller than about onequarter inch, as well as any charcoal dust. In this way, chipped woodcharcoal sized from between about one-quarter inch to aboutthree-eighths of an inch are isolated. This fuel is very high in fixedcarbon as compared to standard lump wood charcoal and as a result asunique and superior cooking properties. The isolated chipped woodcharcoal is then packaged separately from the lump wood charcoal asshown in operation 42, and may therefore be sold as a distinct product.Method 30 then ends as indicated by “done” block 44.

It should be understood that additional screening operations may beimplemented to further size out different sized lumps of charcoal, orfor other purposes. However, the method described herein requires atleast a first sieve to isolate chipped charcoal pieces smaller than afirst size, and a second sieve to isolate those pieces from dust andother pieces smaller than a second size, which is smaller than the firstsize. In this way pieces of relatively consistent desirable size may beobtained. While chipped wood charcoal pieces from between one-quarterand three-eighths inch is provided as an exemplary size, other sizes maybe generated using differently-configured sieves in other embodiments.However, the size from one-quarter to three-eighths inch has beendetermined optimal for passing through typical food supporting grillgrates while still being supportable by a grid 14, when appropriatelysized and configured.

Referring back to FIG. 1, grid 14 may be simply “dropped” into existing,ordinary, grilling devices, without modification thereof, directly ontoa briquette support grate, or radiant bars, heat spreaders, lava rocks,etc., of consumer or commercial natural gas or propane grills. Use ofgas grills as the advantage that chipped wood charcoal fuel 20 may beignited simply by running the gas burners a short time, until ignited,or left on, if desired, for example, to provide extra heat. Onceignited, the gas burners may be shut off. In a charcoal grill, such as aWeber® kettle-style charcoal grill, the chipped charcoal may be ignitedin various ways, from the use of existing electric ignition devices, tousing a butane torch, or even lighter fluid or lighter blocks used forstarting wood fires. Chipped wood charcoal will ignite easily and burnhotter, and leave very little ash in comparison to standard briquettesand other wood fuels. Once fully ignited, cooking may begin immediately,since chipped wood charcoal has very few volatiles (unlike briquettes)and will only enhance the flavor of grilled meats and vegetables.

FIG. 3 shows flowchart 50 illustrating by way of example a method ofgrilling food with grid 14 shown in FIG. 1. This method will bedescribed below with reference to FIG. 1. An initial step, not shown,may include adding grid 14 to an existing consumer or commercialgrilling apparatus, such as a typical solid fuel or gas or propanegrill. The grid may be added simply by lifting food supporting grillgrate 12 and dropping grid 14 directly onto solid fuel support, or in agas or propane grill, heat spreaders, bars, lava rocks, etc., aspreviously described, and then replacing food supporting grill grate 12.Once the grilling apparatus is so configured, method 50 begins asindicated by start block 52 which flows to operation 54, wherein chippedwood charcoal is to grid 14 through food supporting grill grate 12. Aspreviously described, the chipped wood charcoal fuel is sized to easilyfall through food supporting grill grate while grid 14 is configured forsupporting chipped wood charcoal fuel, allowing only minimalfall-through thereof, and providing sufficient airflow to maintainoptimum burning and consequential heat generation. Since the fuel is anatural wood product, any dust or small pieces adhering to the foodsupporting grill grate pose no health risk, and at any rate is likely toburn away during the cooking process.

After the fuel is added to grid 14, it may be ignited by the grillingapparatus's existing gas or propane burners. The gas or propane is usedto ignite the chipped wood charcoal fuel, and then optionally turned offduring cooking. Alternatively, a butane torchor electric ignition devicemay be used to ignite the chipped wood charcoal fuel. Once ignited,method 50 flows to operation 58 where food may immediately be added tothe food supporting grill grate 12 for commencement of grilling. Ifgrilling requires continuous heat over a long period of time such thatadditional fuel is required to be added to grid 14, additional fuel maybe added as shown by operation 60, without lifting the food supportinggrill grate 12 and therefore without interrupting the grilling of food.Then, in operation 62, the food is continued to be grilled after thefuel is added. The method then ends as indicated by “done” block 64.

As explained above, the present invention has significant advantagesover prior food grilling systems. For example, due to high heat output,it provides for decreased food grilling time. Secondly, it provides forinstant, non-stop refueling. Third, the use of natural chipped woodcharcoal adds natural wood grilled food flavors. Fourth, superior dryheat sears food for better internal moisture retention in any kind ofmeat and many vegetables. Fifth, because the chipped wood charcoalcomprises smaller pieces of solid fuel than traditional fuels, itactually packs denser and therefore less is required to grill foods, andfor the same weight in fuel, less storage space than traditional solidwood fuels. These and other advantages would be recognized by expertsand grilling enthusiasts.

Described hereinabove are a method for isolating a unique and desirablematerial useful as fuel for grilling food, a grid for supporting saidfuel within existing traditional solid fuel and gas or propane grillingapparatuses, and a method for using such modified grilling apparatusesfor cooking food and for adding fuel thereof while cooking, in anuninterrupted way.

Although one or more embodiments of the present invention have beendescribed in some detail for clarity of understanding, it will beapparent that certain changes and modifications may be made within thescope of the claims. Accordingly, the described embodiments are to beconsidered as illustrative and not restrictive, and the scope of theclaims is not to be limited to details given herein, but may be modifiedwithin the scope and equivalents of the claims. In the claims, elementsand/or steps do not imply any particular order of operation, unlessexplicitly stated in the claims.

What is claimed is:
 1. A method for isolating high carbon chipped woodcharcoal fuel suitable for food grilling, the method comprising:removing pyrolyzed wood charcoal from a kiln, the pyrolyzed woodcharcoal comprising lumps, chips, smaller pieces, and dust particles;passing the pyrolyzed wood charcoal over a first sieve that isconfigured to separate the lumps from the chips, smaller pieces and dustparticles; passing the chips, smaller pieces and dust particles over asecond sieve that is configured to separate the chips from the smallerpieces and dust particles; and wherein the chips are consistently sizedto be small enough to pass through a food supporting grill grate andsupportable by an underlying grid support.
 2. The method of claim 1,wherein a majority of the chips are at least about one quarter inchalong their longest dimension.
 3. The method of claim 2, wherein amajority of the chips are at most about three-eighths of an inch intheir longest dimension.
 4. The method of claim 3, wherein substantiallyall of the chips are between about one quarter inch along their longestdimension and about three-eighths of an inch in their longest dimension.5. The method of claim 1, further comprising packaging the chipsseparately from the lumps.
 6. The high carbon chipped wood charcoal fuelisolated from pyrolyzed wood charcoal by the method of claim
 1. 7. Thehigh carbon chipped wood charcoal fuel of claim 6, wherein a majority ofthe chips are at least one quarter inch along their longest dimension.8. The high carbon chipped wood charcoal fuel of claim 7, wherein amajority of the chips are at most three-eighths of an inch in theirlongest dimension.
 9. The high carbon chipped wood charcoal fuel ofclaim 6, wherein the chips are packaged separately from the lumps. 10.Chipped wood charcoal, comprising chips of wood charcoal isolated fromexterior surfaces of pyrolyzed wood charcoal lumps, the pieces beingconsistently sized to be small enough to pass through a typical foodsupporting grill grate and supportable by an underlying grid support.11. The chipped wood charcoal of claim 10, wherein a majority of thepieces are smaller than about three-eighths of an inch along theirlongest dimension and larger than about one-quarter inch along theirlongest dimension.
 12. A method for grilling food, the methodcomprising: adding chipped wood charcoal through a standard foodsupporting grill grate to a chipped wood charcoal supporting gridunderlying the food supporting grill grate; igniting the chipped woodcharcoal; cooking food over the chipped wood charcoal; and adding morechipped wood charcoal through the food supporting grill grate withoutinterrupting said cooking.
 13. The method of claim 12, furthercomprising installing the supporting grid to the grill by lifting thefood supporting grill grate and disposing the grid on top of an existingsupport within the grill.
 14. The method of claim 12, wherein theexisting support comprises heat spreaders of a gas grill and theigniting comprises starting the gas grill.
 15. The method of claim 14,wherein the heat spreaders are one of radiant bars, lava rocks, or dripshields associated with a gas or propane burner.
 16. The method of claim12, wherein the existing support comprises a solid fuel support grateconfigured to support charcoal briquettes.